Dr. Yvette Fay Francis-McBarnette in the late 1950s or early ’60s.CreditEarl Owen McBarnette

Yvette Fay Francis-McBarnette, a Jamaican-born medical pioneer in treating children with sickle cell anemia, died on March 28 in Alexandria, Va. She was 89.

Her death was confirmed by her daughter Elayne Sara McBarnette.

Dr. Francis, as she was known professionally, was a high achiever from the time she was a teenager, after immigrating with her parents to New York City from Jamaica.

Raised in Harlem, she enrolled in Hunter College when she was 14, graduating with a bachelor’s degree in physics in three and a half years. Deemed too young for medical school or even a laboratory job, she earned a master’s degree in chemistry from Columbia University instead. In 1946, when she was 19, she became the second black woman to enroll at the Yale School of Medicine.

While directing a clinic at Jamaica Hospital Medical Center in Queens, Dr. Francis was credited with successfully using antibiotics to treat children with sickle cell anemia 15 years before the effectiveness of those drugs was confirmed, in a 1993 article in The New England Journal of Medicine.

During the administration of President Richard M. Nixon, Dr. Francis was named to a White House advisory committee, whose recommendations led to the 1972 National Sickle Cell Anemia Control Act, which appropriated federal funds for screening, counseling, health education and research.

Sickle cell anemia, a genetic disorder that affects primarily blacks and people of Mediterranean origin, produces blood cells that, because they are rigid and shaped like sickles or crescents, clog capillaries and deprive tissues of blood and oxygen. It can lead to organ damage, stroke, blindness, severe pain and death. There is still no cure, except through stem-cell transplants in some cases, but effective treatments can mitigate pain and prolong life.

In 1966, while Dr. Francis was in private practice and an attending pediatrician at Jamaica Hospital, she and several colleagues established a foundation to conduct research into the disease.

By 1970, five years before New York State mandated that infants be tested for it, her clinic had already screened 20,000 children and begun prescribing antibiotics.

Dr. Francis was also urging treatment by then to allow victims of the disease “to pursue their education, earn a living and rear their families” in an era when many sickle cell patients did not survive to adolescence.

One patient who followed Dr. Francis’ advice from childhood, Cassandra Dobson, had children, earned her doctorate in nursing and now teaches at Lehman College in the Bronx.

“I stayed on antibiotics for 35 years,” Professor Dobson said in an interview in 2011 with the journal Yale Medicine, published by the university’s medical school. “If I hadn’t, I would’ve died. I was told I was going to die at 5, at 10, at every milestone of my life.”

Yvette Fay Francis was born in Kingston, Jamaica, on May 10, 1926. Her father, Clarence, a teacher in Jamaica, became a factory worker when he moved to New York and then a delegate for the International Ladies’ Garment Workers’ Union. Her mother, Sarah Francis, who had also been a teacher, became a seamstress. Yvette attended Hunter College High School in Manhattan.

She was breaking ground as a woman — and especially as a black woman — at the very beginning of the civil rights movement. She was a second-year medical school student when she wrote a letter to The Pittsburgh Courier, one of the nation’s leading black newspapers, urging prospective black students to apply. She later said of her white classmates, “We were a close-knit, supportive group.”

Dr. Francis married Olvin R. McBarnette, who survives her. Besides her daughter Elayne Sara, she is survived by five other children, all raised in Queens: Bruce, Camilla, Yvette, Ellen and Andrea, all with the surname McBarnette; three grandchildren; and a brother, Mac Francis.

Dr. Francis was first exposed to sickle cell anemia and its effects during her pediatrics residency at Michael Reese Hospital in Chicago, which served a growing black population migrating from the South. She was the hospital’s first black medical intern.

“I went home and tested all my relatives,” she recalled.

She began practicing medicine at Bellevue Hospital in New York, became director of the sickle cell clinic at Jamaica Hospital and, later, with Dr. Doris L. Wethers and Lila A. Fenwick, started the Foundation for Research and Education in Sickle Cell Disease.

She retired in 2000 and moved to Virginia three years later to be closer to her grandchildren.

When her first patients began living beyond adolescence, Dr. Francis referred them to doctors with adult practices. But when many of her former pediatric patients were reluctant to leave her, she decided, at 52, to pursue a residency in internal medicine and a fellowship in hematology at Bronx-Lebanon Hospital Center so that she could continue to care for them.

Among those patients was Maureen Michel, who was a 9-year-old visiting from Haiti in 1975 when she was hospitalized in New York and referred to Dr. Francis.

“My whole life, every time I go to the emergency room, I call Dr. Francis,” Ms. Michel told Yale Medicine, adding that she always asked, “Do you think this medication is good for me?”

“When she retired,” Ms. Michel said, “I didn’t know if I would ever find any doctor like her, and to tell you the truth, I never have.”